lyndon



E. L YN DON HEADLIGHT LENS Cet. 23 1923.

Filed Sept. 16 1921 3 Sheets-Sheet l P. c 0 0 w.

E. LYNDON HEADLIGHT LENS.

Oct. 23

Filed sept. le.

1921 35 Sheets-Sheet 2 l f r f 1 f [dwf/rd Lynda/z 977m Jl/M'w.

Oct. 23 1923.

E. LYNDON HEADLIGHT LENS Filed' sept. 16

1921 3 Sheet -Sheet 5 RIGHT LEFT Patented Get. 23, 1923.

PATENT OFFICE.

EDWARD LYNDON, OF NEW YORK, N. Y.

HEADLIGHT LENS.

Application led September 16, 1921.

To all whom t may concern:

Be it known that I. EDWARD LYNDoN, a citizen of the United States, and resident of New York city, in the county of New York and State of New York, have invented Certain new and useful Improvements in Headlight Lens, of which the following is a speciiication.

My present invention relates primarily to light distribution, and with regard to its preferred application, to headlights for automobiles and other vehicles.

An object of the invention is to provide a single headlight construction by the use oi which the light will be efliciently distributed in accordance with requirements.

rlhe laws of various States specify that automobile headlights must provide an intensity of illumination of at least a stated minimum. The regulations of many of the more important States, however, are satisfied by the provision of an intensity of illumination toward the left of the car less than the minimum required toward the right. While the latter requirement could be partially met by properly differentiatingl the structures of the two headlights, this introduces among,r others, the diiiiculty of requiringy the manufacture and keeping in stock of left and right headliehts or elements thereof of differentl construction. On the other hand the provision of identical headlights to produce at the left, the same higher intensity that is required at the right results in needless waste of current. while the provision of adjustments for turning a pair of identical headlights toward the right to the proper degree to effect the asymmetrical lie'ht distribution desired. introduces mechanical complications, and detracts from the appearance of the car.

It is an object of the present invention to effect distribution of li glit. to meet the above or any other requirements, without difierentiatinrz the construction of the right-hand headlight from the left Vwithout turning the headlights or either of them from central or neutral position, and without the waste of power incident to providing at any point an excess illumination beyond the minimum specified.

Accordingr to a preferred feature of the invention, I provide a headlight unit, the light-deflecting structure of which is asym- Serial No. 501,020.

metrical with respect to a vertical axial plane, the asymmetry being such as to distribute the light in accordance with requirements.

In the preferred embodiment, the headlight structure includes the ordinary paraboloid mirror with the source of light at its focus, and the headlight lens being provided with a series of integral vertical prismatic conformations asymmetrically formed or disposed in any of a wide variety of ways, some of which are specified below, to effect the asymmetric light distribution desired.

According to another feature of the invention, means is provided for projecting substantially all of the light below a definite level in order to prevent `glare, such means while in itself old and well known, beine; embodied in a unitary construction with the foregoing' means, that is, with the means for projecting the lieht asymmetrically. Broadly, the desired distribution in a horizontal and in a. vertical plane can be achieved by the use either of reflecting or refracting elements or by a combination of both.

In the accompanying drawings in which is shown one or more of various possible embodiments of the several features of the invention, i

Fig. 1 is a diagrammatic view illustrating the minimum requirements of certain State laws,

Fig. 2 is an elevation of a. preferred form of lens.

Fig. 3 is a. sectional view thereof taken along line 3-3.

Fig. 4 is a sectional View taken along line 4.-4 of Fig. l, and

Fins. 5. 6. 7, 7a and 8 are views similar to Fig. 3 of modifications.

Referring now to 1 of the drawings, I have indicated diagrammat-ieally and not to scale the distribution of headlight illumination required in a number of the States. As shown. the requirements are that. there be a minimum illumination of 1200 c. p. at a point which is seven feet to the right of the vehicle. and at a distance of 100 feet in advance thereof, while at the. corresponding pointto the left of the vehicle. the minimum illumination need be but 800 c. p.

In the preferred embodiment, I employ a pair of identical headlights 1 and 2. each inw cluding the usual paraboloid mirror 3, hayL ing; its souree of light et its focus Ll. .lots or lens 5 is of special asymmetric struction to he set orth lielow7 so L .(2 i i JA i :is to reireet the pernllel rays 6 to giro the distribution require i7 that is, to eileet en intensity oi 800 c. to the left or tl l i and 1200 e. p. to tlie iight, or broadly an intensity 50% grleter toward the i than toward the left.

Figs. 2, end. l here shore e oreferred leus ior accomplis-,hiru the distrihution. (hie fece ot the is preferably flet or of uniform curvature e d the other 'ieee 8 irregular. The leue. fiect. comn prises e Succession. oi? pri tie rouiorioetioiis 9. l0, Ill, etc. ideutic@L .n croseeec" slopes. A shoulder 17 eoiiiierts he e end oit each longe slope to the ed.

end of the shorter slope of the euere prisme tic coiiormetioo. .i prisme' o Conformation is thus comooser" of e. narrow prism 18 end :t Wider pris two prisme having edu-.el retract ooo sind delecting the light to=:'ord ooms Y sides. Iii View of the 'feet that the Wider pri ms intercept e greater amount oi? light than the narrower, it follows that eorresporidiugly greater amount of l:U vwill he de- ;ieotod Ytowtrd the rie'ht. The peellel beam from the perfiholie mirror reaching the gris` matic leus is retracted thereby iii the meer iier indicated in dot and dash lines, heli iigziiii es much light being; retracted toward the right es toward the lett. lt will thus follow that it :i source of light ot su'ilioieiit eziiidle power isrsed. the reouireiiieuts above seted and indicated in llig. l would he niet. It will he noted. that the minimum requirements are met hut not exceeded. so that there is uo Weste of currevit. is further seeii that this desirable distrioutioii is eftfected. Without turning; the heedliohts 'from centi-el or neutral posi lt 'iurthei seen that this result .ii'chie'red hy the uee or", the Y eoiel lone 'esh'ihed io :i headlight otherwise ot Ordin Qoiisruetioo.

Any desired means may he eiiiiuloyeil for preventing; glare. Wever, preferably emhoflied gf rel construction with the h iii scribed.. Preferably Shown ier d L 'io leue thicker :it the hottoiii 20 than, the top 2l zuid has e continuous tiier result Y iu e prismetic cou'ormetioii that Will dei'lee' the light dowi'iwer ily es required. equivalent means may he employed if de Tiff. il

. 3 eired. for the purpose oi? eyoi e lere p u ed Iorio .ot

In Fig. 5 is shown e modi lens, generally along the lines ot that shown iii Figs. Q, and Il. in this embodiment, however, the slopes :'22 and corresponding to slopes i2 and le respectively iu 2 here eech o. Qredeteriuined curvature iii` Steed oi being streight.7 'the curvo. ture of the longer slope being' greater than that oil the shorter slope By this menos not only Will e lgreater amount o'j light he teroepted hy the elements to the right ov each Vertex het such gree'er :imouiit will; he refieetel through e 'le theo that will he apparent that by i tures.r any desired ingles oi re. any desired esyirimetric effected.

lu 5 l have showe- :he iuveirtioii7 iii-- o further ri'iodiiiefgl emr/elly similar to hs oit the two opposite eide@ of eeoli erre equal, so that equal eiriouuts tre 'iitereeiited oy the righi' o =.d

slooes 25 end Q6 oi eeoii o' t oouforiuetioiis. The right-ho 26, however. form e greater eul i the normal then the left-houd oiiee. f llows that equal amounts o' lig jt :ire reirec ed to the tiro sides. hut the light toward the right ie retracted i :i `greater than that to'i'v'frd By proper ehoice of the relative ive ample, the desired asymmetric rioution results.

le Figi'. 7 is shown another iiiodiiied form of the invention; The irregular surface Q8 this eiuhoilimeiit consists it a. seriee of identical coiiceve Cylindrical elements or gi'ooree 29 euch extending' iii e vertical plane. the successive oyliiidrioitl eres intorseo'tiiig et vertices 30, the oi: 4e oi he sur eeseive Cylinders being, as shown. upon :i plone A--B iioriiiirig en :ingle with the bounding plane C--D of the continuous or refouler surface 8l of the leiis shown iu the drawings. To eimlyze the i ctiou oi" this leiie upoii the light. reife/rene. had to the auxiliary Figure 7a. This figure shows a fragment ol the lees upon mi enlarged scale A plone lil- F heine' described. te thelgroove and perzillel to the oit the lens, it will he apparent the l son oi? the peculiar erred vneet of C Vliiiders, this tangent plane will Contact the cylindrical are toward the left oi' i center. The excess length 32 oi? the ee o1 the Cylindrical :ire to the right o` lil cession oit' further elements 33 that act to refracta portion of the light toward the right. The light will, therefore7 be well diffused and a sutticient excess will be thrown toward the right to meet require` ments. Obviously, different requirements can be met by providing lenses ot this type with different angles between the locus ot centers and the plane of the lens.

From another point ot view, the segment of the lens between successive vertices as between vertices 30 and 30 comprises two prisms and at opposite sides of the normal plane G-H prism 34 intercepting 'i greater amount of light than prism 35.

it is thus seen that the lens is in etlect made up ot a succession of prisms, arranged in two series, alternatelyv of lesser and greater width, those of greater width refracting an excess oli light toward the right, thereby achieving the asymmetric distribution desired.

From still another point of view. the lens as a whole has a prismatio structure, the thickness increasing gradually from the left toward the right eye. This results in deecting the light as a whole toward the right. The cylindrical grooves act to disperse the light thus thrown as a whole t0- ward the right. the result of this dispersion being to distribute the light in accordance with requirements, part toward the left of the lens and a greater amount toward the right. It will be apparent that in the case of each ot the other 'forms of the invention, the lens may taper from left to right in the same manner.

ln Fig. 8 is shown a still further modifi cation generally similar to that of Fig. 7, the radii of the cylindrical surfaces 40 being. however. of graduated lengths increasing in progression from the left-hand to the right-hand edge ot the lens. the locus plane P-Q oi the cylinder axes being at an angle to the plane of the lens. The slope ot the locus plane is equal to the rate of increase in the cylinder radii, so that a common tangent plane R-S for all of the cylinders will be parallel to the face of the lens. lt will be seen that the refractive angle of; the prism element 42 at the right edge which has the smallest radius is greater than that of the prism element 4-3 to ward thc lett which has the largest radius, and that the refractive angles of the intermediate prisms decrease progressively from prism ft2 to prism 43. Thus. each prism element between successive vertices will uniformly diffuse the light intercepted thereby, but the element ot greater diffusive power being toward the lett Ot the lens. the amount of light retracted toward the right exceeds that toward the left, as required.

ln each ot thev forms o'f the invention it will be understood that the lens will preferably be formed of tapering thickness greater at the lower than at the upper edge substantially as indicated in Fig. 4 although other means may be employed to eliminate glare. In the specific embodiment of Fig. 7, the lens would thus be generally thicker at the right .than at the left and thicker at the bottom than at the top.

It will be seen that in the preferred embodiments, a greater amount of light is retracted toward the right than toward the left, while in certain of the other embodiments, notably in that shown in Fig. 6, equal amounts ot light are deflected toward the two sides, but that toward the right is shifted through a greater angle. ln both forms the refractive power of the parts or elements that. deflect light toward the right is superior to that which operates toward the left, the term refractive power designating the product of amount of light deflected by angle of deflection.

It will be understood that in the use of any ot' the forms of lens shown, n0 occasion will arise for differentiating in any respect between the right-hand and the left-hand lens, identical structures being used for both. rlhe lens. in each case. is simply applied to the ordinary headlight frame in the manner of an ordinary lens. The parallel beam will be retracted by the lens in each case to meet the requirements heretofore noted, an intensity of illumination being provided at a predetermined distance forwardly and toward the right in each case. greater than that toward the left. Obviously by designing the lens in accordance with the foregoing disclosures and by providing a headlight lamp of appropriate candlepower. the light will be projected to produce the intensities required by the laws of certain States, as diagrammatically indicated in Fig. 1.

It will further be seen that though the lens is formed of a single integral piece of glass, the same may be made of composite construction embodying glasses of different refractive indices to produce the asymmetric distribution desired. Obviously. the lens may be modified to produce any desired asymmetric distribution other than that indicated in Fig. l.

It will be apparent that the paraboloidal mirror may be modified in form asymmetrically at its sides, to thereby project more light toward one side than toward the other. but l prefer to effect the desired distribution by retraction as set forth.

It will be apparent that the invention is not confined in its application to headlights. but may be applied broadly for effecting any desired asymmetric distribution of light in any relation.

It will thus be seen that there is herein described apparatus in which the several features of this invention are embodied, and which apparatus in its action, attains the various objects oi" the invention and is well suited to ineet tie requirements of practical use.

As many changes could be made in the above construction and many apparently widely different embodiments of this invention could be inade without departing 'from the scope of the claims, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

I olaiIn:-

l. A headlight lens including one sub-- stantially vertical continuous tace and the other face cornposed of a succession of substantially vertical similar configurations inclined downward with respect to said face, each said configuration having portions sloping laterallyT and asyininetrically toward said vertical face in opposite directions.

2. A headlight lens having a sucression of substantially identical prisma-tic conorinations on one tace thereoit, said conorinations substantially f'ertical for lateral spread of the light, each said conformation being asymmetrical and hai/'ing two surfaces extending in opposite directions 'troni the vertex and forming substantially equal angles with the plane of the lens, the surface to one side of each vertex being longer than the surface to the other side thereof, the longer surface of each of said conformations lying to the same side of the vertex thereof.

3. A headlight lens having; a succession of prisinatic conforniations, the vertices o the successive con'orrnations being substantially equidistant,V said conorrnations substantially rertica for lateral spread of the light, the prisrn surfaces extending at equal angles from opposite sides of a normal plane, the retracting plane toward one side being greater in length than that toward the other the longer surface ot each oit said contormations lying to the same side of the vertex thereoiIl and a subst-ain tially normal shoulder connecting the end of a longer retracting surface with an end ot the shorter relracting surface ot the jacent element.

il. A headlight lens including` an integral refracting structure comprising two sets of prisniatic elements, one set arranced to defleet the light away troni non, al to the and toward one side, the other set arranged to retract the light away roin nor mal toward the opposite side, said prisniatic elements having the same angle of retraction7 those of one set being wider and intercepting a greater quantity of light than those of the other set, wherebj]7 a greater tot-al quantity will be projected touard one side than toward the other.

Signed at New York, in the county of New York and State of New York, this lith day of Sept., A. D. 1921.

EDVARD LYNDON. 

